To fit all fuel injectors and regulators on current TVR engines. This is a high specification FKM Viton O ring which is resistant to the high temperatures experienced under a TVR bonnet. These injector o rings need to be in good condition to ensure no air leaks and fueling issues. This is also the O ring for the fuel pressure regulators on AJP V8, Speed 6 and Rover V8 engines. These O rings should always be replaced if injectors or regulators are disturbed or refitted.